REPORTS. Report of the Committee on Mathematical Tables.—Mr. James Glaisher has undertaken the calculation of the factor tables for the fourth, fifth, and sixth millions, similar to Burckhardt's and Dase's. Burckhardt's tables (Paris, 1814-1817) contain the least factor of every number not divisible by 2, 3, or 5, from unity to three millions, and Dase's tables (Hamburg, 1862-1865) give similar information for the seventh, eighth, and ninth millions. Dase undertook the calculation at the suggestion of Gauss, who urged him to begin at 6,000,000, as the three millions between 3,000,000 and 6,000,000 had been calculated by Crelle and presented to the Berlin Academy, and Gauss did not doubt that they would be published sooner or later. It appears, however, that the Berlin manuscript is too inaccurate to admit of publication, and therefore, in order to fill up the gap, it is necessary to undertake the calculation again, as the nature of the work is such that errors committed do not readily admit of discovery and correction. Mr. Glaisher has completed the portion from 3,000,000 to 4,039,500, which is ready for press, and the remaining two millions are being actively proceeded with.